Ali Bagherian kalat; Esmail Filekesh; Alireza Majidi
Abstract
Marl formations due to their unsuitable physico-chemical properties have low vegetation cover and so are highly erodible. These formations make up about 2000 km2 of lands in Sabzevar and Davarzan areas. In this research, geology, pedology and vegetation cover of marl formations were studied. Geologically, ...
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Marl formations due to their unsuitable physico-chemical properties have low vegetation cover and so are highly erodible. These formations make up about 2000 km2 of lands in Sabzevar and Davarzan areas. In this research, geology, pedology and vegetation cover of marl formations were studied. Geologically, there are two kinds of marl formations consisting salty and red gypsiferous marls. Marly lands in southern aspects usually have no vegetation but in northern aspects the vegetation varies between 0 to 27 percent. Three vegetation communities consisting of Salsola aucheri, Artemisia seiberi and Ephedra intermedia are stablished on marly soils. For recognizing soil factors of each vegetation community, studies localized in establishment area of Salsola, Ephedra and Artemisia vegetation types. Many soil profils were dug. Soil samples were taken from depth between zero and 40 cm of marly soils and were analyzed. Results showed that in all plant types with increasing of percent of plant cover from 0-10 to 10-24 percent, the main soil factors such as EC, pH, gypsum, silt an clay, Na+, K+, Mg2+, Cl-, So42-, total Cations and Anions and SAR were decreased and factors such as Organic carbon, N, P. T.N.V, Co3-1 and sand percent were increased. The statistical analysis of data was conducted with the SPSS software. This study showed that Artemisia and Ephedra had the highest and lowest vegetation percentages, respectively. Analyzing of data acording to Duncan Test showed that the differences between plant cover percent in three vegetation communities are very obvious (P<0.05). Meanwhile, the amount of EC and gypsum of marly soils were important soil factors that had the most roles in establishment of vegetation.
Ali Bagherian Kalat; Gholamreza Lashkaripour; Mohammad Ghafoori; Aliakbar Abbasi
Abstract
On areas with highly eroded soils, where vegetation is absent or negligible, runoff generation and erosion processes can greatly be affected by the nature of parent material. This research was carried out to investigate the effects of lithology and soil parent material on erosion and soil loss, using ...
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On areas with highly eroded soils, where vegetation is absent or negligible, runoff generation and erosion processes can greatly be affected by the nature of parent material. This research was carried out to investigate the effects of lithology and soil parent material on erosion and soil loss, using rainfall simulator in Sangerd Drainage Basin which is located in Khorasan Razavi Province. To do this research, 11 homogeneous soil units (map units) with the same slope (20%), land use (rangeland), different lithology (marls and conglomerate) and erosion facies (sheet-rill, rill and rill-gully) were selected. A rainfall simulator producing 36 mm h-1 rainfall intensity and 30 minute duration was used at 33 locations over soil erosion plots. The amount of sediments was measured. In order to investigate factors affecting on soil erosion and sediment yield, soil was sampled from 0-15 cm depth of plot adjacent areas. For statistical analysis, SPSS 22 was used. Results showed that soil erosion and sediment yield have meaningful differences in different lithologies. Eem-RG and Plc-SR soil units with 260.9 and 45.1 gr m-2 have the most and the least sediment yield, respectively. It was found that the sediment yield had positive correlation with some soil properties such as silt, Ec, pH, SAR and antecedent soil moisture and negative correlation with sand, OC, NPV, vegetation and rock fragment cover.
